Cyclone Yaas is gearing up to wreak havoc on the eastern coast. The major Yaas, May 2021 impact of the cyclonic system is expected across the north-eastern coastal districts of . is anticipated to bear the maximum brunt of wind and rainfall with some impact on , primarily driven by surge and First Advisory rainfall-induced floods, particularly in the coastal districts. Additionally, very A deep depression (50-61 kmph) over East-central has rough to high seas, squally weather and gale winds around the system centre intensified into Cyclonic Storm Yaas (62-88 kmph) as per the IMD Bulletin on will affect shipping vessels and fishing operations from May 24-26, 2021. May 24, 2021 at 0830 IST. It is very likely to intensify into a Severe Cyclonic Storm (89-117 kmph) in the next 12 hours and further into a Very Severe POTENTIAL IMPACTS Cyclonic Storm (118-166 kmph) in the next 36 hours. The cyclonic storm is The below table provides a brief overview of the potential rainfall impacts over forecasted to move north-north-westwards, crossing north Odisha-West several Indian States. Bengal coasts between Paradip and Sagar on May 26. The VSCS is expected to Table 1: Forecasted impact2 on the States in the next 48 hours - Rainfall bring heavy to extreme rainfall to Odisha, West Bengal and southeast . State 24th May 25th May 26th May 27th May The Bay of Bengal accounts for only 5% of tropical globally, but Light to moderate tropical cyclones on the eastern coast of India results in 80% of tropical Andhra at many Heavy to very cyclone-induced fatalities worldwide due to the shallow continental shelf that Pradesh Heavy to very heavy places; heavy at 1 (North at isolated places amplifies storm surges and a very dense population . In India, tropical heavy falls isolated places Coastal) cyclones usually occur in April-May (pre-monsoon season) and October- at isolated November (post-monsoon). places Heavy to very Heavy to very heavy Heavy to very In 2020, there were two pre-monsoon cyclones – Amphan (Super Cyclonic Light to heavy rainfall rains at a few places heavy rainfall at moderate Storm) impacting the eastern coast of India, and Nisarga (Severe Cyclonic in the north with extremely heavy isolated places in at many Storm) impacting the western coast. Cyclone Yaas comes only a week after an Odisha coastal falls in , north interior places; districts; , , Odisha Extremely Severe Cyclonic Storm (ESCS) struck India’s west heavy falls Isolated heavy Mayurbhanj heavy to coast, killing 104 people. In addition to the ongoing devastating second wave at isolated of Coronavirus, India is witnessing challenges from cyclones also. to very heavy very heavy falls at a

2 Spatial rainfall distribution: Isolated: <25%, A few: 26-50%, Many: 51-75%, Most: 76-100%; Rainfall amount (mm): Heavy rain: 64.5 – 115.5, Very heavy rain: 115.6 – 204.4, Extremely 1 Neetu, S., et al. "Premonsoon/postmonsoon Bay of Bengal tropical cyclones intensity: Role of air‐ heavy rain: 204.5 or more sea coupling and large‐scale background state." Geophysical Research Letters 46.4 (2019): 2149-2157.

1

State 24th May 25th May 26th May 27th May The below table provides a brief overview of the potential wind impacts places rainfall is few places in over several Indian States. likely over , south coastal , , Table 2: Forecasted impact on the States in the next 48 hours – Wind districts Keonjhar State 24th May 25th May 26th May 27th May Extremely heavy Heavy to very Squally wind Squally wind rainfall at isolated heavy rain at Andhra (40-50 kmph (50-60 kmph places over isolated places in Pradesh gusting 60 gusting to 70 Light to , Medinipur, Malda & moderate at North & south 24 Darjeeling, (north) kmph) near the kmph) near many places; Parganas, Howrah, Dinajpur, coast the coast heavy to very Hooghly, and Kalimpong, heavy over heavy to very heavy Jalpaiguri; heavy Nearly half of Bhadrak Squally wind West Bengal Medinipur, rainfall at a few rain at a few and some parts of (55-65 kmph Kendrapara will gusting to South & north places over Nadia, places over Squally wind Squally wind experience gale winds 75 kmph) 24 Parganas, Bardhaman, Bankura, Bankura, Purulia, (40-50 kmph (50-60 kmph Howrah and Purulia, Bhirbhum Bardhaman, (155 gusting to 180 Odisha gusting 60 gusting to 70 Hooghly and heavy falls at Bhirbhum & kmph) 6 hours before kmph) near the kmph) near districts isolated places over Murshidabad landfall; Baleswar will coast the coast Murshidabad, Malda experience gale wind and Dakshin Dinajpur (135-145 gusting to Districts 160 kmph) at landfall Heavy to very Sikkim heavy rain at Squally wind Squally wind Gale wind (60-90 Squally wind isolated places (40-50 kmph (50-60 kmph kmph gusting to 100 (55-65 kmph West Bengal gusting 60 gusting to 70 kmph) at landfall gusting to Light to moderate kmph) near the kmph) near 70 kmph) Light to moderate at at many places; coast the coast many places; heavy heavy to very to very heavy rainfall heavy rainfall at Jharkhand Squally wind (40-50 at isolated places; isolated places; Jharkhand kmph gusting 60 extremely heavy over extremely heavy kmph) near the coast southeast Jharkhand over southeast Jharkhand Light to moderate Light to moderate at at many places; Assam & many places; heavy heavy to very Meghalaya to very heavy rainfall heavy rainfall at at isolated places isolated places

2

ANALYSIS RMSI has analysed potential flood and wind impact due to Cyclone Yaas (based on the IMD bulletin on May 24, 2021 at 0830 hours IST). The following maps depict the potential flood and wind affected areas. As per the available information, Cyclone Yaas will affect the following districts considerably due to wind hazard: Baleswar, Bhadrak, Cuttack, Jagatsinghpur, Jajpur, Kendrapara, , Mayurbhanj districts of Odisha, East Midnapore, and West Midnapore districts of West Bengal and East Singhbhum district in Jharkhand.

Figure 1: Potential impact due to wind - Cyclone Yaas Figure 2: Potential impact due to flood in Odisha - Cyclone Yaas

3

North 24 Parganas, Murshidabad in West Bengal and Bhadrak, Kendrapara, Jagatsinghpur, and coastal areas of Baleshwar districts of Odisha will potentially be affected by floods due to Cyclone Yaas.

------DISCLAIMER: This report contains information generated through the analyses, and model predictions based on data provided by IMD and compiled using proprietary computer risk assessment technology of RMSI Pvt. Ltd. The technology and data used in providing this information is based on the scientific data, mathematical and empirical models, and encoded experience of scientists and specialists (including without limitation, earthquake engineers, wind engineers, structural engineers, geologists, seismologists, meteorologists, and geotechnical specialists). As with any model of physical systems, particularly those with low frequencies of occurrence and potentially high severity outcomes, the actual losses from catastrophic events may differ from the results of simulation analyses. RMSI specifically disclaims any and all responsibilities, obligations and liability with respect to any decisions or advice made or given as a result of the information or your use thereof. RMSI specifically disclaims any and all responsibilities, obligations and liability including all warranties, whether expressed or implied, with respect to the report, including but not limited to, warranties of non-infringement, merchantability and fitness for a particular purpose. In no event shall RMSI (Or its subsidiary, or other affiliated companies) be liable for direct, indirect, special, incidental or consequential damages with respect to any decisions or advice made or given as a result of the contents of this information or your use thereof. The material contained in this report is the copyright of RMSI and may be used only for informational purposes only. RMSI makes no representations or warranties with respect to this information. For using any information from this report, you agree to the terms and provisions as outlined in this disclaimer. If you do not agree to them, please do not use this report.

Figure 3: Potential impact due to floods in West Bengal - Cyclone Yaas

4